1. Field of the Invention
This invention relates to a detector array assembly and, more particularly, to a detector array assembly in which "bump" interconnect members are used to provide electrical and/or mechanical connections between two substrates fastened together under pressure as, for example, by a cohesive material such as epoxy.
2. Description of the Prior Art
Prior art detector arrays have been assembled with "bump" interconnects joining two substrates. More particularly, raised areas of conductive and relatively soft and fusible material such as indium are located on each substrate. One of the substrates carries detector material such as mercury cadmium telluride for detecting radiation, particularly infrared radiation, and the other substrate carries electrical circuitry for interfacing the detectors with external signal utilization apparatus. The raised portions are then joined together to provide mechanical stability and electrical connections between the elements located on the two substrates. The two substrates may then be bonded together with, for example, an adhesive epoxy. In co-pending application Ser. No. 145,828, entitled "Method and Apparatus for Testing Equipment Having Compressible Contacts" filed in the name of Peter H. Zimmerman et al on Jan. 19, 1988, and assigned to the assignee of the present invention, a temporary "bump" interconnect arrangement is shown utilizing indium for producing a good electrical contact between the detector mounted on one base and a test station on the other base. Since the connection is temporary in this co-pending application, the permanent bonding of the two substrates is not shown; but when the two bases are to be permanently connected together, they are commonly joined by an epoxy backfill. A difficulty arises in utilizing epoxy, however, since upon hardening the epoxy tends to compress the two bases together and in doing so, while providing good electrical contact and mechanical strength, also causes the indium bumps to penetrate into the detector material itself which often causes unreliable operation.